grammar, inheritance, and the law

I took a grammar class last week and learned something new. When I was in school one could choose if they wanted to put a coma before the word 'and' when listing things. So, a sentence would be correct either way:

I like the colors green, read and blue.
I like the colors green, read, and blue.

I guess a few years ago there was a legal suit over an inheritance. The will said "I leave my entire estate to Tom, Fred and Janet." Well, apparently Tom sued over the fact that he should get half and Fred and Janet should split the other half (as oppose to everyone getting a third) because there was no comma after Fred. Tom won. And now the rest of us have to use a comma before 'and' when making lists.

I don't know how this is relevant to my life or why I find it so interesting, I guess it really showed me how important grammar is when I usually don't care so much about grammar.